Reverse Osmosis Water Filters for Producing Water With Selectable Total Dissolved Solids

Abstract

Methods and apparatus for providing water with a selectable total dissolved solids content. The apparatus includes a reverse osmosis filter system to provide filtered water having a dissolved solids content less than the selectable total dissolved solids content and for mixing water having a dissolved solids content exceeding the selectable total dissolved solids content with the filtered water in a ratio to provide water with the selectable total dissolved solids content. Various embodiments are disclosed.

What is claimed is: 
     
         1 . A method of providing water with a selectable total dissolved solids content comprising:
 reverse osmosis filtering of water having a dissolved solids content exceeding the selectable total dissolved solids content to provide filtered water having a dissolved solids content less than the selectable total dissolved solids content;   mixing water having a dissolved solids content exceeding the selectable total dissolved solids content with the filtered water in a ratio to provide water with the selectable total dissolved solids content.   
     
     
         2 . The method of  claim 1  wherein the water having a dissolved solids content exceeding the selectable total dissolved solids content is supplied by a municipal water supply. 
     
     
         3 . The method of  claim 1  wherein the reverse osmosis filtering is done with a reverse osmosis filter using squeeze water to pressurize filtered water in a storage tank for causing the mixing of water having a dissolved solids content exceeding the first predetermined total dissolved solids with the filtered water in a ratio to provide and dispense water having the selectable total dissolved solids content. 
     
     
         4 . The method of  claim 3  wherein the water having a dissolved solids content exceeding the selectable total dissolved solids content is supplied by a municipal water supply, and wherein the squeeze water is coupled to the municipal water supply during dispensing of the water having the selectable total dissolved solids content. 
     
     
         5 . The method of  claim 4  wherein the squeeze water is coupled to the municipal water supply during dispensing of the water having the selectable total dissolved solids content by coupling a municipal water supply side of a reverse osmosis membrane to provide the squeeze water and to flush the municipal water supply side of the reverse osmosis membrane. 
     
     
         6 . The method of  claim 5  wherein the ratio for mixing water having a dissolved solids content exceeding the selectable total dissolved solids content with the filtered water to provide the water with the selectable total dissolved solids content is manually adjustable. 
     
     
         7 . The method of  claim 5  wherein the flow rate of the water having a dissolved solids content exceeding the selectable total dissolved solids content is shaped to match the flow rate of the filtered water to mix in a constant ratio over a range of flow rates during dispensing of the water having the selectable total dissolved solids content. 
     
     
         8 . The method of  claim 7  wherein the method is practiced using a self-contained reverse osmosis filter system that operates responsive to changes in the pressure of the water with the selectable total dissolved solids content at an outlet of the reverse osmosis filter system. 
     
     
         9 . The method of  claim 8  wherein the self-contained reverse osmosis filter system includes a pressure regulator to regulate the pressure of the water having a dissolved solids content exceeding the selectable total dissolved solids content received from the municipal water supply. 
     
     
         10 . The method of  claim 9  wherein the self-contained reverse osmosis filter system is a mechanical system and is operative without electricity. 
     
     
         11 . The method of  claim 1  wherein the ratio for mixing water having a dissolved solids content exceeding the selectable total dissolved solids content with the filtered water to provide the water with the selectable total dissolved solids content is manually adjustable. 
     
     
         12 . The method of  claim 1  wherein the flow rate of the water having a dissolved solids content exceeding the selectable total dissolved solids content is shaped to match the flow rate of the filtered water to mix in a constant ratio over a range of flow rates during dispensing of the water having the selectable total dissolved solids content. 
     
     
         13 . The method of  claim 1  wherein the method is practiced using at least one self-contained reverse osmosis filter system that operates responsive to changes in the pressure of the water with the selectable total dissolved solids content at an outlet of the reverse osmosis filter system. 
     
     
         14 . The method of  claim 13  wherein the self-contained reverse osmosis filter system includes a pressure regulator to regulate the pressure of the water having a dissolved solids content exceeding the selectable total dissolved solids content received from the municipal water supply. 
     
     
         15 . The method of  claim 13  wherein the self-contained reverse osmosis filter system is a mechanical system and is operative without electricity. 
     
     
         16 . Apparatus for receiving water having a first dissolved solids content exceeding a selectable total dissolved solids content and providing water with the selectable total dissolved solids content at an apparatus output comprising:
 a reverse osmosis water filtering system for receiving the water of a first dissolved solids content exceeding the selectable total dissolved solids and providing at a reverse osmosis water filtering system output, filtered water having a second dissolved solids content less than the selectable total dissolved solids content, the reverse osmosis water filtering system having a squeeze water system for dispensing from the reverse osmosis water filtering system output;   a second line coupled between a squeeze water line of the reverse osmosis water filtering system and the apparatus output, the squeeze water line having squeeze water pressure therein and;   a flow rate adjuster in the second line;   whereby during dispensing, squeeze water pressure will cause the reverse osmosis water filtering system to dispense filtered water having a second dissolved solids content less than the selectable total dissolved solids content, together with squeeze water, which when mixed in a proportion set by the flow rate adjuster, provide the filtered water having the selectable total dissolved solids content.   
     
     
         17 . The apparatus of  claim 16  further comprising at least one check valve to prevent backflow from the apparatus output to the second line or to the reverse osmosis water filtering system. 
     
     
         18 . The apparatus of  claim 17  wherein the at least one check valve comprises a first check valve in the second line and a second check valve in the reverse osmosis water filtering system output. 
     
     
         19 . The apparatus of  claim 18  further comprising an on/off valve in the second line, whereby the flow of squeeze water through the second line may be shut off to selectively dispense the filtered water having a second dissolved solids content less than the selectable total dissolved solids content. 
     
     
         20 . The apparatus of  claim 16  wherein the flow rate adjuster is manually operable. 
     
     
         21 . The apparatus of  claim 16  wherein the reverse osmosis filtering system includes a pressure regulator regulating pressures therein. 
     
     
         22 . The apparatus of  claim 21  further comprising a flow rate shaper in the second line for shaping the flow rate of the squeeze water in the second line to match the flow rate of the filtered water having a second dissolved solids content less than the selectable total dissolved solids content over a range of flow rates of the filtered water having a second dissolved solids content less than the selectable total dissolved solids content. 
     
     
         23 . The apparatus of  claim 22  wherein the on/off valve is a ball valve. 
     
     
         24 . The apparatus of  claim 16  wherein the filtered water having a second dissolved solids content less than the selectable total dissolved solids content and squeeze water are mixed and dispensed from a common apparatus output. 
     
     
         25 . The apparatus of  claim 16  wherein the reverse osmosis filter system is configured to couple to a municipal water supply, and wherein the squeeze water is coupled to the municipal water supply during dispensing of the water having the selectable total dissolved solids content. 
     
     
         26 . The apparatus of  claim 25  wherein the reverse osmosis filter system couples the squeeze water to the municipal water supply during dispensing of the water having the selectable total dissolved solids content by coupling a municipal water supply side of a reverse osmosis membrane to provide the squeeze water and to flush a municipal water supply side of a reverse osmosis membrane. 
     
     
         27 . The apparatus of  claim 16  wherein the reverse osmosis filter system is a self-contained reverse osmosis filter system that operates responsive to changes in the pressure of the water with the selectable total dissolved solids content at an outlet of the reverse osmosis filter system. 
     
     
         28 . The apparatus of  claim 27  wherein the self-contained reverse osmosis filter system is a mechanical system, thereby being operative without electricity.